Typically, an unfinished basement floor is made of concrete. While concrete is a practical material for a house's foundation, it isn't a very pretty surface to look at. Fortunately, most epoxy paints work well on concrete, and you can transform a gray basement floor into a colorful focal point. To get the best results, however, you must prep the floor properly before you paint. Good prep work leads to an even, durable finish.
Sweep the basement floor with a broom.
Vacuum dust and debris out of cracks and small divots in the basement floor. A broom removes surface debris, but most basement floors contain recessed imperfections that require vacuuming before patchwork can begin.
Fill cracks and dents with concrete patching compound. Use a putty knife to slather the patching compound onto the area. Paint won't hide imperfections; fixing cracks is an important part of painting prep.
Smooth out patched cracks with a patching trowel. Wait for the patching compound to dry. Quick-drying compounds harden in less than one hour, while other varieties can take a full day. Consult the container for the manufacturer's recommended drying times.
Apply painter's tape to trim and adjacent wall surfaces.
Mix 1 part muriatic etching solution with 10 parts water in a large bucket. Muriatic etching solutions are available at most hardware stores, and this cleanser is specifically designed for masonry surfaces.
Wash the floor with the diluted muriatic etching solution and a mop. Wait for the floor to fully dry before applying paint.